


No Matter the Form

by cdra



Series: Kinktober 2019 [16]
Category: Fire Emblem Series, Fire Emblem: Fuukasetsugetsu | Fire Emblem: Three Houses
Genre: Kinktober, Kinktober 2019, Masochism, Nonbinary My Unit | Byleth, Other, Outdoor Sex, Transformation, byleth is a dragonfucker and a masochist
Language: English
Status: Completed
Published: 2019-10-17
Updated: 2019-10-17
Packaged: 2020-12-16 12:44:15
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,308
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21036440
Author URL: https://archiveofourown.org/users/cdra/pseuds/cdra
Summary: Afflicted by an unusual side-effect of his Crest, Claude inadvertently begins to turn into a dragon. Byleth isn't as bothered as they should be.[Kinktober Day 17 - Transformation]





	No Matter the Form

**Author's Note:**

> *sweats.* I got nothing to say for myself on this one. Byleth's a gremlin and so am I.
> 
> Oh, I guess it's worth noting that I was imagining afab Bylad here, but you're totally free to consider other options such as afab Bylass, scraggly nb gremlin Byleth, and so forth, because all Byleths are valid but I apparently can't _not_ call them they/them.
> 
> Also, with this, I finally have more FE works than Pandora Hearts ones, which is Neat.

He had really hoped that, if nothing else, no one would see this happen again. And if anyone _did _see, if Claude let himself slip in front of _anyone_, he would’ve hoped that it wasn’t Byleth—he doesn’t want them worried about him, and he sure as _hell _doesn’t want to hurt them on accident, especially after five years of schemes turned paper-thin balancing acts without them.

But—but, on the other hand, at least it’s Byleth. Byleth’s pale eyes don’t hold a hint of judgement within them, even as Claude’s breathing turns ragged and he curls in on himself to hide the symptoms. Anyone else would run away—Byleth runs to his side, instead, despite how Claude stumbles backwards in some vague attempt to elude them, into the stone of the abandoned fort that they’ve holed up in for the night.

Their fingers tentatively reach for Claude’s shoulder. “Claude? Are you injured?”

He lifts an arm to try to shake them off, hissing unconsciously from the pain. Oh, if it were that _simple_. If something about fighting that winged, draconic beast in the desert hadn’t made Claude’s blood thrash and sizzle in his veins—if Failnaught didn’t burn against his palms, leaving a crawling sort of discomfort along his wrists, the itch of skin going dry and changing texture clawing at his senses.

Byleth jerks their hand back instinctively and frowns at him, but doesn’t back off—because of course they wouldn’t. “You’ve been acting strange since we got back,” they observe matter-of-factly. “If you’re hurt, we need to get a healer. You know better—”

“_Byleth_,” Claude grumbles from behind the arm he’s got over his mouth—his teeth itch behind it, and it makes his voice unsteady. “It’s not like that, I swear. It’s—” a lump forms in his throat; explaining himself isn’t his specialty. “I can handle this on my own—it’s nothing I haven’t done before.”

Their brows are raised, eyes almost unnaturally keen as they watch him breathe. It’s like they can see right through him—it’s part of their magnetism. “Your eyes…” Damn, of _course _Byelth would see it even in the pale twilight; Claude flinches and presses his spine against stone, but something about doing so only brings his attention to the way his bones seem to crawl under his shoulderblades, and his spine all but ripples with something inhuman.

Claude inhales deeply, and forces himself to meet Byleth’s gaze. They won’t back off—he can’t weasel his way around them. His cheeks prick with the rough sensation of white scales growing against the line of his beard. “It’s… another side effect of my Crest,” he explains, his voice a bit frayed, “But this hasn’t really happened since… the first time I used House Riegan’s Relic, five years ago. Earlier, I… something about that thing we fought… it made my blood go hot.”

Without a hint of shame or cognizance of what they’re really _doing_, Byleth reaches out and gently pushes his arm down, away from his face. Their other hand cups the back of his head, which is—both really weird, and kind of reassuring. It’s beyond shameful, having the scales that blossom steadily along his cheeks revealed to them—not to mention his tongue, a little too-long as it trails past his lips and he pants; his teeth, sharpened uncomfortably and just a little too large for his mouth; his eyes, brilliant green with pupils pulled into slits.

“Teach,” he almost whines, frowning uneasily under their stare, “c’mon, don’t go silent on me _now_.”

“You’re… stunning,” their eyes are sincere despite how they don’t exactly smile, so they’re not telling one of their poor-taste jokes—and it makes Claude’s heart stutter.

“...What?” he nearly croaks; the ivory scales crawl their way up his arms in a sudden, nervous skitter, and his fingers twitch as his claws sharpen. Byleth sighs tiredly, and Claude shivers as he fights to keep still. There’s some kind of instinct boiling in his chest, ready to overflow—fight or flight, or something a little darker still, he’s not quite sure what it is.

“Look, I… I really might hurt you, if you stay that close,” Claude argues softly; he puts his no-longer-human hand to their chest, nudging them back but not forcing them. His other hand twitches at his side, still soft and blunt, and his gaze falls to the ground, no longer able to look Byleth in the eye. It’s almost like he can _smell _them—it’s uncomfortable, and it makes the painful wildfire in his chest spread to a different kind of fire, deeper in his core.

“I don’t want to leave you alone, like this,” they say, stubborn, setting a hand atop his on their chest. “Won’t you do something worse, if no one’s here to keep an eye on you?”

He’s not sure if they’re right or not, but the pain is making it harder and harder to think; his breathing is harsh and uneven. His claws scrape against their breastplate, unable to push them away. When he meets their eyes again, his own are wild and frazzled, while theirs are steady as ever. It’s not fair, really. Claude always holds himself together so expertly, but in the end, he can’t keep the seams together forever without leaning on Byleth.

Something spills over within him, past the boiling point and melting, and Claude hears a growl in his own throat as his vision fogs over and his gaze goes distant. The strings he keeps attached at his joints to control his own movements snap—the delicate balance between them tips, and he slams Byleth against stone with a clawed hand at their throat, the other beside their head. Somehow, they don’t look afraid, even now, even as his fingers tense against the wall and the transformation consumes them, too.

“Teach,” he pleads in a voice that seems to be underwater, “_Teach_, my dear friend, don’t let me…” But they _do _let him, not resisting as he pushes closer and pulls their jacket away so his fangs can graze against their neck. Like it doesn’t matter at all, to them—like they’re _fine _with this, with Claude warped and monstrous and breathing hotly against their skin. “Don’t let me _hurt you_,” he whimpers; his claws catch on their sleeves and his hips roll against them, the fire in his body manifesting into an ugly, confused sort of arousal. A mixed-up poison of pains that turn to pleasure, both burning through his skin as his spine threatens to crawl out from his back.

“I won’t,” they say easily, reaching up to touch his cheek once more. “You’re in a lot of pain, right? Let me help.”

Claude chokes back a cry as the pressure in his back tightens to the point of bursting—he sinks his teeth into Byleth’s shoulder to abate the sound. A tail, long and glistening ivory, flicks behind his body under no control of his own; each movement feels terribly sharp, like his bones are being constantly rearranged, and it makes his vision blurry.

Byleth makes a soft sound of realization and their hands immediately grow busy undoing his armor and clothes—they’re probably worried about him damaging it. Leave it to Teach to think about that kind of thing when Claude’s busy losing his mind from the overwhelming burning and itching and boiling just under his skin. His hands scramble for purchase, unknowingly tearing through their undershirt until his claws catch and tug at skin, leaving angry, desperate red lines behind.

But, Byleth is _strong_. If they wanted him off, they could easily rebuff him even without drawing their blade. If they minded the fact that blood is welling out from where his fangs meet their flesh, they could toss him aside like a ragdoll—yet, they don’t. That _has _to mean it’s okay—he _has _to trust them to stop him if he’s too much, because Claude can’t trust himself, right now.

The wings are the worst of it, a sensation of ripping and tearing and reconstituting sinew that leaves Claude shaking and gasping in Byleth’s arms. Somehow, they got most of his armor out of the way, but the wings still rip their way through his shirt mercilessly, just as a scream rips from his throat unmuffled as he throws his head back. His claws sink into the meat of their ribs, past the tears and runs in their shirt, and draw blood in thin rivulets. Against all odds, something throbs hotly between his legs, _wanting_.

Claude shudders as he slumps against Byleth, his gaze hazy and far-off. His veins burn and pulse with the aftershocks of something between pain and ecstasy; as he gasps for air, he realizes that the nagging, itching feelings of the change are beginning to subside in slow waves, replaced by echoes of heat and need that find his eyelids fluttering.

“Is it over?” Byleth asks quietly, a bit breathlessly; Claude’s head lolls slightly as he tries to get a glimpse of their expression. Despite the fact that he can still taste their blood on his over-long tongue, they don’t look all that troubled—Byleth must have crazy pain tolerance levels.

“_Byleth_,” he slurs, “I feel… I’m… mm.” It’s terribly hard to form words; he pulls them close by the waist instead, jaw slack and panting, and he presses his hips, or more specifically the stiff bulge between his legs, against them by way of an explanation.

“Ah.” They seem to understand, if that soft sound is any indication; even at that, they don’t move to stop him.

Claude grumbles in a drunken, nonsensical way as his palm curls aggressively around Byleth’s ass. “S… stop me, if…” he manages, barely, his eyelids heavy as he rolls his hips against theirs again.

For whatever reason, instead of recoiling, they groan softly, and it scrambles up Claude’s thoughts even more. “I will,” Byleth assures him as they spread their legs a bit wider. “Don’t worry so much.”

He can’t, really, because he’s a bit preoccupied with the heat that clouds his thoughts; Claude gasps harshly as he ruts against Byleth, his expression far-gone and overcome. They laugh softly and, once more, help him out, this time undoing the clasps on both his pants and their own. His head may be full of static and noise, but Claude picks up on their intentions easily—he growls and lifts their legs, holding them up against the wall with surprising ease.

Byleth shudders in his grasp, and Claude gives a thoroughly-intoxicated sort of smirk. With their knees over his shoulders he rocks his hips again, but now his cock meets their slit and the wet heat of it is practically enough to melt him. “Byleth, _fuck_,” he gasps absently, claws digging into their thighs. His tail flicks in agitation, still a bit beyond his control; his cock’s gotten bigger, too, and it throbs hungrily with the resonant heat in his system.

Their nails scrape at his now-bare, scale-pocked shoulders, seeing some sort of purchase. “Claude,” they mutter airily, “Do it—don’t hold back.”

It’s a damn easy request to follow. Claude growls against Byleth’s ear as he stretches them open with a sharp rock of his hips—he drinks in the way they cry out softly, muted but laden with heat. His nerves flare up as their heat envelops him; it feels insanely good, in a completely different way than the usual. Byleth’s name drips from his lips as he holds them tight, rocks his way into a steady yet harsh rhythm—and they reward him with quiet moans and sobs, so much more expression than he could’ve _ever _wrung from them in the past. Were he not already drunk on the fire that still smolders in his form, he could _easily _become so from hearing Byleth make sounds like that.

“Claude, more, like _that—_” Byleth gasps as they wrap their arms around his neck; all he can do is oblige them, shifting his angle in accordance with what makes their voice peak the most. He loses himself in it, in their hushed pleas and their ragged breaths, until it starts to be too _much _and he growls in warning, knowing he won’t last.

They don’t stop him, even now. Claude fucks into them to the hilt and stars overcome his vision—he comes with a rumbling sound caught in the pit of his throat, the heat that’s consumed him reaching a desperate peak and lighting into a blaze through his body. His nails dig into their skin; Byelth clenches around him and whines something incomprehensible, signaling that they hit their climax, too.

The two of them tumble to the ground in a mess of limbs and sweat and heaving breaths as Claude loses a bit of his momentary, madness-fueled strength. He lies against them for a moment, panting, and lets the overwhelming sensations settle under his skin into something akin to normalcy. Byleth’s fingers run through his wiry hair, down to the scales at the base of his neck; Claude shudders on the inhale as they touch there.

“Hey,” Byleth mutters, their fingertips trailing down toward the base of his wings thoughtfully, “How long does this last?”

Claude glances up at them and blinks a few times, deerlike. “That… I don’t really know. Sorta lost track of time, last time.”

“Think it’ll last long enough to go again?” Byleth is really brazen, when they want to be, and it leaves Claude staring dumbfounded. “I mean… I want to know what that tongue can do, at the very least.”

He can’t help how a smirk curls at his lips—Claude huffs a sigh through his nose. “That’s the first thing on your mind?” He mumbles, only half-surprised. “Fine, fine… lemme catch my breath, then we’ll see.”

**Author's Note:**

> claude, distressed: the safeword is PUNCHING ME IN THE FUCKING FACE, BYLETH, OKAY???  
byleth, giving a thumbs up: nice


End file.
